In a rotary electric machine using permanent magnets for a rotor, in particular, in a high-characteristics rotary electric machine using rare earth sintered magnets, the magnets have a high proportion of the motor cost and therefore the magnetic flux of the magnets is required to be effectively utilized. Here, an interior magnet rotor has advantages that, for example, the usage amount of magnets is small and the rotor can withstand high-speed rotation, as compared to a surface magnet rotor. Therefore, such interior magnet rotors are applied to many products. However, the interior magnet rotor has a disadvantage that magnetic flux short-circuit occurs at a bridge portion as a boundary between magnetic poles. Accordingly, as a structure for suppressing the magnetic flux short-circuit, it is proposed that a coining work is performed so as to decrease the sheet thickness of a bridge portion of a steel sheet for core. In the coining work, for example, by a punch and a die, the steel sheet is worked so as to decrease the sheet thickness thereof, whereby a coined portion is formed.
Further, the following is proposed. A plurality of embedding holes as magnet insertion holes are provided to which permanent magnets are mounted, and magnetic path narrowed portions as bridges are provided between the embedding holes and the peripheral part of an electromagnetic steel sheet (steel sheet of rotor). Electromagnetic steel sheets are stamped plural times to form the magnetic path narrowed portions and the plurality of embedding holes. At the same time as the plural stamping works, the magnetic path narrowed portions are subjected to a pressure so as to be squeezed, whereby the sheet thicknesses of these portions are decreased. Thus, the magnetic characteristics of the magnetic path narrowed portions are deteriorated, whereby a magnetic flux short-circuited via each magnetic path narrowed portion is reduced and a magnetic flux that works effectively is increased (see, for example, Patent Document 1).